Piston and connecting rod



July 5, 1932. A E D 1,866,057

PISTON AND CONNECTING ROD I Filed May 25, 1929 2 Sheets-Sheet 1 fizz/973207 QZZQTZ y 7015 %%7'7Z%9.

July 5, 1932.

A. E. REID 1,866,057

PISTON AND CONNECTING ROD Fild May 25, 1929 2 Sheets-Sheet 2 "t si'tion of a piston rod he had tot 5 develops i provide for adequate and between the piston and connecting rod, wholly dispensing with the unis nnnnn" n nun), on 13;:

or nuoonnrnn, nassacn'usnrrs, a conronarron er ACH USETTS, ASSIGNOfi T0 it 218520291 @QHPANY,

rrs'rcn arm connnc'r me non Application med y 86,

This invention necting rods of the connectin the piston to t rtains to pistons and cont at genera type in which rod transmits motion from e crank shaft without interpoand cross head and wherein the piston has a hollow body or skirt portion into which one end of the connecting rod projects. Such pistons are common-f trunk pistons and are almost.

1y known as universally employed in internal combustion en ines.

{ li/iodern practice in internal combustion 011- gine design tends to an increase in speed-with a corresponding) decrease in cylinder and piston diameter, at at such high speeds the pressures developed between the arts are very great so that most thorough in rication is necessary in order to avoid heating and excessive wear. On the other hand, at such high speeds, the usual wrist pin employed for uniting the iston and connecting rod must he of large diameter to withstand the stresses imposed upon it and to afford the necessary bearing surfaces, but this lar e wrist pin takes up so much of the space wit in the small piston that splash lubrication of the bearin 1s seriouslyl interferred with and resort mu e provision of oil channels lengthwise oi the connecting rod. This practice weakens the rod and does not always rovide a. dependable andadequate source 0 cation and as a result of thehi h pressures "between the piston, wrist'pinan connecting red, the parts wear so of use.

wrist pin and often times the reborin of the journal openings in the iston and in accordance with t a ependable lubrication of the bearings usual wrist in, while" at thef same time pro-n.

vidin'gthe car the hearing surfacesfat a distance .rrem the pieton head so that.dangersotoverheatin and oil carbonization tomatic. com

esired-large hearingusuriaces: to.

tion: for-:such wearasma developfifrom long continuedwme ;;1I..provi e lubrithat knocking often after a comparatively short period This necessitates replacement of the resent invention .member removed;

thrust pressure; I. arrange such. 'Lbearingmem r.;. I

is eliminated; :I provi e an a connection between the rod and iston such that the rod may he disconnecte from the piston without removing the latter from the engine cylinder; 1 provide a connection of universe. oint type which allows the piston complete freedom to rotate relatively to the cylinder wall; and I embody all of the above advantageous features in a simple construction capable of manufacture at a cost not substantially exceeding the cost of production of usual arrangements.

While my invention is particularly applicable to internal combustion engine use, I contemplate that it is not restricted thereto but may be found useful in thermal motors of other terms as well as in pumps, air compressors and the like. Accordin ly, while for convenience of description an illustration, I may hereinafter make reference to the present invention as embodied in an internal combustion engine I do not intend thereby to restrict the scope of the invention or to limit its field of use. Moreover, while I herein describe certain desirable embodiments of my invention, it is to m understood that the illustration and description of such embodiments is b way of example only and that internal combustion engine;

- Fig. 2 isaxfragmentary view showingthe I end orti onofthe connecting rod;

Fig.3 is a bottom planview of the i \withthe connecting rodandmovable bearing Fi 4 is a transverse sectionon a line 4-4 of Fig.2; i

in section and to-"smallersc'ale the connecting .rodand lower and omittin Fig. 6isa compositeview illustratingthe aloweror movable bearin member;

Fig.7 is a composite'vlew illustratinf glone desirable resilient retainer member;

5 is a fragmentary *side'view of the piston partly able Fi 8 is a side elevation showin the movaring member assembled with the retainer spring;

Fig. 9 is a view similar to Fig. 5 but showini a modified construction;

\ ig. 10 is a composite view illustrating a spring device employed in'the construction of Fig. 9; and I Fig. 11 is an edge elevation of a resilient retainer provided with tension adjusting means.

Referring to the drawings, the numeral 1 indicates a portion of the cylinder of an internal combustion engine having the head 2. The iston 3 which is arranged within the v c lin or is provided with a head 4 and the s '11: portion 5, this piston being of the type usually known as a trunk iston. T e connecting rod 6 is provided at its lower end with the usual journal bearing for the reception of the crank 7, and at its other end with a ivot member, here indicated as of spherica contour, ada ted to cooperate with a hearing carried b t e piston to form an articulated joint tween the piston and rod. While a spherical head is here indicated and for certain purposes is preferable, I contemplate that in the broader aspects of the invention, a cylindrical or other shape of head may be found useful.

Preferably the head 8 is provided with an oil duct 10, here shown as aligned with the axis of the rod 6, and with a circumferential oil distributing groove 9, here shown as disposed in a lane at right angles to the axis of the rod. no or more auxiliary ducts 11 lead from the main duct 10 into the bottom of the groove 9.

Within the piston I arrange a fixed bearing 12 which is spaced from the inner surface of the piston head so as to leave a substantially unobstructed chamber above it, and which is preferably fixed in position by means of a plurality of webs 13 uniting it to the iston wall. Preferably the bearing memr 12 and the webs 13 are integral with the piston proper. In the preferred'construction, the outer or lower end of the fixed bearing member 12 is of cylindrical contour as in icated at 14, while its inner or upper art is of dome-like shape as shown at 15. he exact outer contour of this hearing is not essential to the resent invention, but it should be noted that it is spaced from the side walls and head of the piston so as to provide free 1 to oil s lashed from the crank case up into the hea end of the piston. Prefera l the inner end of the fixed bearing member 12 is furnished with an upstandm .an-

nular rib 16 defining an oil-receivin asin 17 havin a downward! concave ttom. The fixed aring 12 is ho low and an oil pas- Sage 19 leads from the bottom of the basin 17- u t: the interior'of the hollow bearing mem-e l The inner end of the cavity or chamber within the fixed bearing member is of spherical curvature as shown at 20, while the outer portion of this cavity is of c lindrical curvature as shown at 21, the cavity being open at its outer end. Preferably the cylindrical portion of the cavity is of somewhat greater diameter than the spherical portion 20, leaving a shoulder 22 between these surfaces, and I preferably provide a pluralit of circumferential space oil passages'23 eading from this shoulder 22 to the outside of the bearing member.

Cooperating with the fixed bearin memher I provide a movable or lower caring member,preferably comprising a plurality of independent and separable parts, .here shown as the parts 24and 25, although this bearing may be divided into a reater number of segments if desired. As 5 own, (Figs. 6 and {3) this movable bearing is of annular form, each of the members 24 and 25 constituting a half circle. The inner portion of the movable bearin member is furnished with a spherical sur ace 26 ada ted to coo erate with the surface 20 of the fixed bearing to form a socket for the reception of the end 8 of the connecting rod. The lower portion of the movable bearing is preferably furnished with a more or less conlcal inner surface 27 adapted to accommodate the connecting rod 6 as the latter swings with the crank. The outer end of the movable bearing also referably comprises a radial shoulder or ange 28 and a projecting rib 29 having a beveled outer surface.

I also provide a resilient retainer device or snap ring 30 consistin of a piece of spring metal shaped to provide an annular portion and a plurality of projecting legs 31 each of which is turned downwardly at lts outer end as, shown at 32. The 0 enm at the center of the part 30 is prefera 1y 0 such diameter that w on the member 30 is laced over the beveled rib 29 of the mova le bearin it will engage the beveled surface of the ri at an intermediate oint. The lower endof the piston is furnis ed with an inwardly proecting abutment rib 33 whose upper or inner surface is machined ofl' accurately to form a seat for the ends'of the legs 31 of the retainer device.

In assembling the the ball 8 at the end 0 first thrust through the openin in the retainer device and is then push upwardly into the cavity in the fixed bearing member. The arts 24 and 25 of the movable bearing are t en assembled around the rod and telescoped within the cylindrical outer portion of the fixed bearing in which the movable bearing fits with a snug but sliding fit. The spring retainer device is now pushed upwardparts above described,

y into engagement with the beveledsurface 29 and its legs are snapped up above the rib the connecting rod is bearing, securely holding t e bearing in position'with its s herical surface in resilient contact with the ower portion of the ball 8. At the same time the pressure of the spring member against the beveled surface of rib 29 causes the members 24 and 25 of the bearing to engage each other closely so that theparts are all held firmly in assembled relation. If desired, as shown-in Fig. 11, the spring retainer may be provided with adjusting screws adapted to' engage the flange 28 of the movable bearing member and thereby to vary ahilpsressure of the lower bearing against the In the arrangements shown in Figs. 9 and 10, the parts in general are similar to those above described except that the movable bearing B consists of. a plain ring divided into segments if desired, and which is held in position within the fixed bearing by means of a screw-threaded collar engaging an internally screw-threaded portion of the bearing 12.- Interposed between the ring B and the collar 35 is aspring 36 preferably consisting of a washer-like member or spring steel or other suitable material having struck-up therefrom the fingers 37. In this arrange- 'ment, as well as that above described, the

lower or movable bearing B is resiliently held against the ball 8 so asautomatically to take up ware which may develop between the ball and the wall of the socket as formed by the spherical surfaces of the fixed'and movable bearing members.

In both forms of the device the bearing for the upper end of the connecting rod is spaced from the-piston head and from the walls of the piston, and there is a free passage for oil which may collect upon the inner surfaces of the piston head and which is assisted in dropping therefrom into the basin 17 by a pointed projection 18 on the inner surface of the piston head. This oil flows freely down through the passage 19 and out through the ducts 11 into contact with the surface of the ball 8, thus providingvery efiicient lubrication for the parts. The connecting rod may readily be removed from the piston without withdrawing the piston from the cylinder by removal of the snap spring 30 in the case of Fig. 1 or by unscrewing the collar 35 of the device shown in Fig. 9. In the arrangement,

other and equivalent arran ments ma be provided as occasion may emand wit ut departing from the spirit of the invention and I regard all such substitutions of eguivalents and immaterial chan es in detail and dimensions of parts as fa ling within the scope of my invention as expressed in the ap nded claims.

claim:

1. The combination of a piston and a connecting rod, the piston having a bearing comprising a fixed art and a movable part co-- operating to de ne a socket, the rod having a member adapted to fit within said socket and with the latter to form an articulated joint, 8. circumferentially extending abutment rib projecting from the inner surface of the piston, and a spring having an element which engages the movable bearing part and a plurality of legs resting upon the abutment rib.

2. The combination of a piston and a connecting rod, the piston having a bearing comprising a fixed part rigid with the piston and having a cavity of substantially spherical curvature facing away from the head of the piston, and a movable part also having a A cavity of substantially spherical curvature, said cavities cooperating to form a socket. a ball on the end of the rod adapted to fit within said socket, a sprin comprising an element engaging the mova le bearing part and a plurality of outstanding legs, and means carried by the piston providing supports for said legs, whereby said spring may e effective for constantly urging the movable bearing part toward the fixed bearing art. p 3. The combination of a trunk iston and a connecting rod, the piston having an internal bearing comprising a fixed part rigid with the piston and having a cavity of substantially spherical curvature facing away from the head of the piston and an annular part movable with respect to the piston when assembled and also having a cavity of substantially spherical curvature, said cavities cooperating to form a socket, the connecting rod passin member and having a ball fitting within the socket, a spring having an annular portion through which the rod passes and which engages the movable bearing part, and legs projecting from the annular portion 'of the spring into engagement with the piston.

4. The combination of a trunk piston and a connecting rod, the piston having an internal bearing comprisin a fixed cavity of substantially spherical curvature and an annular-movable part also having a cavity of substantially spherical curvature, said cavities cooperating to form a socket, said annular movable part comprising a plurality of independent substantially segmental sections, and means engageable with the segmental sections andwith the side walls art having a f through the annular movable of the piston for holding said sections in assemble relation and for retaining the movable part of the bearing in cooperative relations ip to the fixed part, the connecting rod assing throu h said annular part and having a head fitting within said socket.

5. The combination of a trunk piston and a connecting rod, the piston having an ternal bearing comprising a fixed part spaced from the inner surfaces of the piston head and side walls and having a concave bearing surface facing away from the head of the iston, .said part having an oil collecting asin disposed between said fixed part and the head of'the piston and having free and unrestricted communication with the interior of the piston, the bearing having a socket, an oil passage leading from the basin to the socket, and a head on the connecting rod co- 6 operating with said socket to form an articulated 'oint.

6. The combination of a trunk piston and a connecting rod, the piston having an internal bearing comprisin a fixed part spaced from the inner surfaces 0 -the piston head and side walls and having a concave bearing surface facin away from the head of the piston,

said art aving an oil collecting basin dis-' pose between said fixed part and the head of the piston and having free and unrestricted communication with the interior of. the piston, the bearing having a socket, an oil passagle leading from the basin to the socket, and a end on the connecting rod cooperating with the socket to form an articulated joint, said head having oil ducts adapted to distribute oil from said passage over the inner surface of the socket.

7 The combination of a trunk iston and a connecting rod, the piston having an internal bearing comprising a fixed part spaced from-the inner surfaces of the piston head.

and side walls, said part having an oil collecting basin at the inner end, the bottom of the basin being concave, the bearing having a socket, an oil passage leading from the basin to the socket, and a head on the connecting rod cooperating withthe socket to form an articulated 'oint, said head having a main duct adapte in certain positions of the rod to ali with the; oil passage, a circumferential oil distributing groove, and branch ducts leading from the main duct to said groove.

8. The combination of a trunk piston and a connecting rod, the piston having an internal bearing comprising a fixed part having a cavity of substantially s herical curvature facing away from the hea of the piston and an annular movable art also having a cavity of substantially sp erical curvature, said cavities cooperating to form a socket, and a head on the connecting rod adapted to fit with said socket, the fixed bearing part having circumferontially spaced oil passages leading inwardly to the crevice between the fixed and movable bearing parts.

9. The combination of a trunk piston and a connecting rod, said piston having a concentrically arranged fixed bearing member spaced from the inner surfaces of the piston head and side walls and integrally united to the latter by spaced webs, said member having a cavity therein, and an annular movable bearing member cooper-able with the fixed member to provide a socket for the inner end of the connecting rod, said movable member comprising a plurality of segments adapted to be assembled around the connecting rod, and resilient means engageable with the annular bearing member and with the side walls of the piston for retaining said segments in assembled relation.

10. A trunk piston having a head and side walls, said piston having a concentrically arranged fixed bearing. member spaced from the inner surface of the head and side walls of the piston, said bearing member having an internal cavity opening at its outer end, and an integral annular rib at the inner end of the bearing formin an oil basin, said basin having free and unrestricted communication with the interior of the piston, the bearing member having a passage leading from said basin directly to the cavity.

11. A trunk piston having a head and side walls, said piston having a concentrically arranged fixed bearing member s aced from the inner surface of the head an side walls of the piston, said bearing member being hollow and having cylindrical side walls and a dome-like inner end, and an annular rib rojecting from the dome-like surface of the aring member to form an oil collectin basin, said basin havin free and unrestricted communication with t e interior of the piston, the bearin member having a passage leading from t e basin directly to its interior.

12. A trunk piston having a head and side walls, said piston having a concentrically arranged fixed bearing member spaced from the inner surface of the head and side walls of the piston, webs integrally uniting the bearing member to thepiston wall, the bearin member being hollow and having cylindrical side walls and a dome-like inner end, the bearing having a cavity which is of spherical curvature at its inner end and which is cylindrical near its outer end, the bearing member having passages for conducting oil to the cavity, a movable annular bearing member freely movable through the outer end of the cavity and telescoping within the cylindrical portion of said cavity, the inner end of the movable bearing member having a spherically curved surface, and resilient means urgingsaid movable bearing member inwardly relatively to the fixed bearing member.

13. The combination of a piston and a connecting rod, the piston having a bearing comprising a fixed art and a movable part cooperating to de no a socket,'said fixed part having a bearing surface facing away from the head of the piston and a lower end having an internally screw-threaded portion, a screw-threaded collar coaxial with the fixed bearing member engaging the internally l0 screw-threaded portion of the fixed bearing member, a rod having a member adapted to fit within said socket and with the latter to form an articulated joint, and an annular spring interposed between the collar and the movable bearing member, said spring comprising a washer-like member havmg a plurality of acclivous resilient fingers for re taining the movable bearing member in position.

14. A trunk piston having a head and side walls, said piston having a concentrically arran ed fixed bearing member s aced from the inner surface of the head an sidewalls of the piston, webs integrally unitingmthe hearing member to the piston wall, the aring member being hollow and having cylindrical side wallsand a dome-like inner end, the bearing having a cavity which is of spherical curvature at its inner end and which 80 has an internally screw-threaded portion at its outer end, the bearin member having passa es-for conducting oil to the cavity, a mova le annular bearing member-telesco ing within the cylindrical portion of sald 85 cavity, the inner end of the movable bearing member having a spherically curved surface, a screw-threaded collar engagin the internally screw-threaded P01171011 0% the fixed bearin member, and a spring member inter- 40 posed tween the collar and the movable bearing member, said spring member comrising a washer-like collar having a plurallty of resilient fingers urging said movable bearing member inwardly re atively to the fixed member.

Signed by me at Boston, Massachusetts, this 23rd day of May, 1929. Y ALLAN E. REID. 

